1. Field of Invention
The present invention relates to a vehicle light bulb applied to automobiles and other types of vehicles.
2. Related Art
With reference to FIG. 5, a conventional automobile light bulb comprises a glass bulb (40) and a base (41) that securely receives the glass bulb (40) therein. Two filaments (42,42xe2x80x2) each connected between two respective conducting legs (43a, 43b, 43c, 43d) are provided in the glass bulb (40), wherein each conducting leg (43a, 43b, 43c, 43d) has a wire (not shown) that extends into the base (41). Usually, the wires extending from the conducting legs (43a, 43c) are connected together to form a common wire. When the glass bulb (40) is adhered to the base, the common wire is disposed to electrically connect with the inner wall of the base (41), wherein the base (41) is made of conductive material and is used as one electrode, such as a cathode. Other wires, which extend from the conducting legs (43b, 43d), are electrically connected to a conductive point (44) formed on the bottom of the base (41), wherein the conductive point (44) is used as the other electrode, such as an anode.
When the conventional automobile light bulb is being installed in a socket of a signal light, such as a brake light or a turn signal, the base (41) and the conductive point (44) are respectively and electrically connected to the cathode and anode of the socket. Thus the automobile light bulb is activated when the socket is provided with power.
However, such a structure of the conventional light bulb has some defects that need to be overcome. When the glass bulb (40) is adhered with the base (41) by using viscose, one essential point is that the common wire must be electrically connected with the base (41) well, if not, the light bulb will not light up.
Another defect appears at the time when the conventional light bulb is being installed in the socket. With reference to FIG. 5, two stubs (45) are further symmetrically formed on an outer periphery of the base (41). The installation of the light bulb into the socket is as follows. The glass bulb (40) is gripped by a user and the base (41) is pushed into the socket, whereafter the glass bulb (40) is rotated so as to find a proper position whereby the two stubs (45) are able to engage with the corresponding mechanism in the socket.
Since the connection between the glass bulb (40) and the base (45) is only achieved by the viscose, once the light bulb has been installed and detached from the socket several times, the glass bulb (40) and the base (45) may separate due to the torque between the bulb and the base. An even worse situation is that once the light bulb is damaged and needs to be replaced with a new one, the separated base (44) may possibly still remain in the socket and be very hard to take out, thus the replacement of the light bulb becomes very difficult.
Therefore, the present invention provides a vehicle light bulb to mitigate and/or obviate the aforementioned problems.
The main objective of the invention is to provide a vehicle light bulb that is convenient to install in or detach from a socket of a signal light in a vehicle.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.